JP2006049703A - Charged particle beam lens array, and charged particle beam exposure apparatus using the charged particle beam lens array - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an electronic lens array with less crosstalk and high voltage applicable thereto, and to provide a manufacturing method of the array. <P>SOLUTION: In the electrically charged particle beam lens array, an upper electrode 521, intermediate electrodes 522 and a lower electrode 523 are sequentially arranged with a plurality of openings. Shield electrodes 524 and 525 having a plurality of openings are disposed between the upper electrode 521 and the lower electrode 523. The shield electrodes electrically float and a voltage applying means 515 is connected to the intermediate electrodes 522. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

The present invention belongs to the technical field of charged particle beam lenses used in exposure apparatuses using charged particle beams such as electron beams, and particularly relates to an electron lens array in which electron lenses are arrayed.

  In the production of semiconductor devices, electron beam exposure technology has been spotlighted as a promising candidate for lithography that enables exposure of fine patterns of 0.1 μm or less, and there are several methods.

One of these methods is a multi-beam type exposure system that draws a pattern simultaneously with multiple electron beams without using a mask, eliminating the need for physical mask fabrication and replacement, and has many advantages for practical application. It is to be prepared. What is important in making an electron beam multi-purpose is the number of arrays of electron lenses used for this. The number of beams is determined by the number of electron lenses that can be arranged inside the multi-beam type exposure apparatus, which is a major factor in determining the throughput. For this reason, how to reduce the size while improving the performance of the electron lens is one of the keys to improving the performance of the multi-beam exposure apparatus.

Japanese Patent Application Laid-Open No. 2004-55166 (Patent Document 1) is a patent document showing an example of an electron lens array used in a multi-beam type exposure apparatus. FIG. 12 is a cross-sectional view of the electron lens array 300. Here, the electron lens array 300 is disclosed as an array of Einzel lenses by aligning three electrodes 301 using fibers 302 and grooves 304 formed on a Si substrate. A conductive shield electrode 303 is provided between the fiber 302 and the electron beam passage region to prevent the fiber 302 from being charged up. Fabrication is performed using micromechatronics technology. In addition, a multi-beam type exposure apparatus using the electron lens array 300 is disclosed.

Japanese Patent Application Laid-Open No. 2001-345259 (Patent Document 2) is a patent document showing another example of an electron lens array. FIG. 13 is a cross-sectional view of the electron lens array 400, where 401 indicates an electrode and 403 indicates a shield electrode. Here, the electron lens array 400 discloses a structure in which a shield electrode 403 is provided between the electron lenses in a direction parallel to the optical axis to prevent crosstalk between the beams. Again, the fabrication is done using micromechatronics technology.
JP 2004-55166 A JP 2001-345259 A

However, the conventional electron lens array is insufficient in the following points.
Since alignment is performed by the fiber and the groove formed in the Si substrate, there is a limit in bringing the three electrodes close to each other. For this reason, the voltage to be applied is increased, and the apparatus becomes large.

  Regarding the latter of the conventional example, a shield for preventing crosstalk is provided, but the potential gradient between the electrodes is not uniform, and it is considered that there is a limit in reducing crosstalk.

  SUMMARY OF THE INVENTION An object of the present invention is to provide an electronic lens array for a multi-beam type exposure apparatus that solves the problems in the prior art and has a simpler configuration with less crosstalk and to which a high voltage can be applied. It is what.

  In order to achieve the above object, the present invention provides a charged particle beam lens array in which an upper electrode, a middle electrode, and a lower electrode each having a plurality of openings are arranged in this order. The shield electrode is disposed at least one of between the electrode and the middle electrode and between the middle electrode and the lower electrode, and the shield electrode has substantially the same shape as the middle electrode.

  The present invention may be characterized in that, for example, the shield electrode is electrically floating, a voltage applying means may be connected to the shield electrode, and the voltage applying means may be connected to the middle electrode. The middle electrode may be electrically independent for each row of the openings.

  Further, the present invention may be characterized in that an interval between the middle electrode and the shield electrode is 1/10 or less of an opening pitch of the middle electrode, and between the upper electrode and the middle electrode and the A plurality of shield electrodes may be arranged between at least one of the middle electrode and the lower electrode, and any two of the upper electrode, the middle electrode, the lower electrode, and the shield electrode Among the electrode intervals, the interval between the middle electrode and the shield electrode may be the smallest.

  An exposure apparatus according to the present invention includes a charged particle beam that emits a charged particle beam, a correction electron optical system that includes a plurality of intermediate images of the charged particle source and the charged particle beam lens array described above, and the plurality A projection electron optical system for reducing and projecting the intermediate image onto the exposure target; and a deflector for deflecting the plurality of intermediate images projected onto the exposure target so as to move on the exposure target.

  Further, the present invention provides a method for producing a charged particle beam lens array in which an upper electrode, a middle electrode, and a lower electrode each having a plurality of openings are arranged in this order. Between the middle electrode and at least one of the middle electrode and the lower electrode, and plating any one of the upper electrode, the middle electrode, the lower electrode, and the shield electrode The method may include a step of forming using chemical vapor deposition and a step of forming the plurality of openings using sacrificial layer etching.

  In addition, the device manufacturing method according to the present invention includes a step of exposing the exposure target using the charged particle beam exposure apparatus, and a step of developing the exposed exposure target. .

  According to the present invention, it is possible to provide an electron lens array with less crosstalk and capable of applying a high voltage with a simpler configuration.

  The best mode for carrying out the present invention will be described in detail with reference to the accompanying drawings.

<Electronic lens array>
An electronic lens array 500 according to an embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a conceptual diagram of an electron lens array 500, showing a 3 × 3 array. In the figure, the electron lens array 500 has a structure in which an upper electrode 521, an upper shield electrode 524, an intermediate electrode 522, a lower shield electrode 525, and a lower electrode 523 each having a plurality of openings are sequentially stacked. Have. The upper electrode 521 has a thin film structure formed of a conductor, and a plurality of openings 528 are arranged in a lattice shape (centering on each intersection of vertical and horizontal virtual straight lines). The lower electrode 523 has the same configuration, and a plurality of openings 514 are formed at the same position (corresponding position) as the opening 528 of the upper electrode 521. The middle electrode 522 is an electrically independent (insulated) electrode group for each column (y-axis direction). The middle electrode 522 has a plurality of openings 510 at the same position (corresponding position) as the opening 528 of the upper electrode 521. The upper and lower shield electrodes 524 and 525 have the same configuration as the middle electrode 522. By matching the openings of the electrodes in a planar shape, the electron beam EB can be passed through the openings.

In the charged particle beam lens array, the middle electrode is electrically independent for each row of the openings, and by connecting a voltage applying means to the middle electrode,
The focal length for each particle beam can be controlled for each column.

  In the figure, two upper and lower shield electrodes 524 and 525 are shown for simplicity, but the number of shield electrodes to be laminated is changed according to the required specifications, specifically, about 2 to 10 layers. Further, it is desirable to stack the same number of upper shield electrodes 524 and lower shield electrodes 525. Further, it is desirable that the stacking interval is sufficiently small with respect to the pitch of each opening, and it may be an equal interval or an unequal interval. In particular, reducing the distance between the middle electrode 522 and the shield electrode installed closest to the middle electrode 522 is effective in reducing crosstalk. The upper electrode 521 and the lower electrode 523 are electrically grounded. The middle electrode 522 has voltage application means 515 independently for each of the A, B, and C columns. Further, the upper and lower shield electrodes 524 and 525 are characterized by being electrically floating (insulated).

In a charged particle beam lens array in which an upper electrode, a middle electrode, and a lower electrode each having a plurality of openings are sequentially laminated, a shield electrode having a plurality of openings is laminated between the upper electrode and the lower electrode. Thus, crosstalk between adjacent columns can be reduced.

  In the above charged particle beam lens array, since the shield electrode is electrically floating, the potential of the shield electrode is determined by the potential of the upper electrode, the middle electrode, and the lower electrode, thereby reducing crosstalk with a simple configuration. can do.

  In the above charged particle beam lens array, a plurality of shield electrodes are stacked between at least one of the upper electrode and the middle electrode and between the middle electrode and the lower electrode, so that the potential gradient between the electrodes is substantially uniform. It becomes easy to make crosstalk small.

Next, the operation of the electron lens array 500 having the above configuration will be described. In the electron lens array 500, a potential of 0V is applied to the upper electrode 521 and the lower electrode 523, a potential of −1000V is applied to the A and B rows of the middle electrode 522, and −950V is applied to the C row of the middle electrode 522. Assume that the adjacent potential difference between the B row and the C row is 50V. At this time, the potential of each shield electrode is defined by the potential of the upper electrode 521, the lower electrode 523, and the middle electrode 522 of each column. Since the potential in each shield electrode is considered to be uniform, the gradient of the potential between the electrodes becomes almost uniform for each column, and the electron lens array 500 with little crosstalk can be realized.
Although the example in which the shield electrode is floated has been described above, a voltage applying unit may be connected to the shield electrode so that the shield electrode has a desired potential.
That is, (1) a planar shield electrode is disposed between the upper electrode 521 and the middle electrode 522 in each row and (2) a planar shield electrode is disposed between the lower electrode 523 and the middle electrode 522 in each row. Thus, the influence of the electric field in the column can be suppressed, and crosstalk can be suppressed satisfactorily.

  In the charged particle beam lens array, since the voltage applying means is connected to the shield electrode, the shield electrode can be regulated to an arbitrary potential, and the focal length and the like for each particle beam can be finely controlled.

  Next, the electron lens array 500 according to the embodiment of the present invention will be described in detail according to a structure actually formed. 2A is a perspective view, FIG. 2A is a cross-sectional view taken along line AA ′ in FIG. 2A, FIG. 2B is an enlarged view of the rectangle shown in FIG. 2A, and FIG. FIG. 2B is a cross-sectional view taken along the line BB ′ in FIG. 2-1. Although a 1 × 2 array is shown for simplicity, an array of several tens × several tens is actually formed. In the drawing, the electron lens array 500 has a structure in which an upper electrode 521, an upper shield electrode 524, an intermediate electrode 522, a lower shield electrode 525, and a lower electrode 523 each having a plurality of openings 528 are sequentially stacked. The lower electrode 523 is formed on the substrate 501. A shield electrode 529 is provided on the lower surface of the substrate 501. Further, a silicon dioxide 507 is formed on the upper surface of the substrate 501, and the substrate 501 and the lower electrode 523 are electrically insulated. The opening 528 has a diameter of 80 μm and a pitch of 200 μm. The structure of each electrode is as described above. In addition, each electrode may have a conductive surface, and may have a conductive film formed on an insulator. Each electrode is electrically insulated via a wall-like insulator 526. The insulator 526 is made of silicon dioxide or the like. Further, the insulator 526 is not necessarily required if the electrodes are insulated from each other and the distance between the electrodes can be maintained. Detailed dimensions are shown in Fig. 2-2. In particular, since the electrode interval and the number of shield electrodes are directly related to the performance of the electron lens array 500, they are important factors and are determined by desired specifications. In the case of this embodiment, the electrode spacing (separation) dimension is 10 μm, the thickness dimension of each electrode is 5 μm, the dimension between the end faces of adjacent electrodes is 20 μm, the shortest dimension from the inner surface of the opening to the end face of the electrode is 50 μm, The shortest dimension from the inner surface to the inner wall surface of the insulating layer 526 is 40 μm.

  In the charged particle beam lens array, the distance between the middle electrode and the shield electrode is 1/10 or less of the pitch of the openings of the middle electrode, so that the crosstalk can be sufficiently reduced.

  In the above charged particle beam lens array, the distance between the middle electrode and the shield electrode is the smallest among the gaps between the electrodes, so that it is difficult to make the potential gradient uniform in the vicinity of the middle electrode. The potential gradient between the electrodes can be made substantially uniform by the number of shield electrodes, and crosstalk can be easily reduced.

  Next, with respect to the manufacturing method of the electron lens array 500 having the above structure, FIGS. 3-1 (a) to (f) and FIGS. 3-2 (g) to (i) which are AA ′ cross-sectional views in FIG. This will be described with reference to FIGS. 3-3 (j) to (k) and FIGS. 3-4 (l) to (m). Again, for simplicity, a 1 × 2 array will be described. For example, it manufactures by performing the process shown to the following (1)-(13).

(1) A substrate 501 is prepared. The substrate 501 is made of single crystal silicon and has a thickness of, for example, 200 μm. The thickness should just support the structure mechanically. Next, silicon dioxide 507 having a film thickness of 1.5 μm is formed on the front and back surfaces of the substrate 501 by using a thermal oxidation method (FIG. 3A).

(2) A seed layer 502 is formed on the upper surface of the substrate 501 by continuously depositing titanium / gold with a thickness of 5 nm / 100 nm, respectively. Moreover, the film thickness of titanium should just work of adhesion | attachment promotion, and is used in the range of several nm-several hundred nm. Further, gold used as the conductive layer is used in the range of several tens of nm to several hundreds of nm (FIG. 3-1 (b)).

(3) A novolac resist 508 is applied to a thickness of about 10 μm, and photolithography is performed to form an electroplating mask. Thereafter, copper electroplating is performed using a copper sulfate plating solution until the thickness reaches about 5 μm to form the lower electrode 523 (FIG. 3C).

(4) The substrate 501 is immersed in an organic solvent such as acetone, ultrasonic cleaning is performed, and the resist 508 is removed. Next, reactive ion etching using a gas such as chlorine or argon is performed, and titanium / gold is etched to remove an unnecessary portion of the seed layer 502 (FIG. 3D).

(5) About 10 μm of PSG (phosphorus glass) is formed using atmospheric pressure CVD or the like to form the insulator 526. Thereafter, the insulator 526 is patterned by photolithography (FIG. 3E).

(6) About 15 μm of film or resin polyimide is formed to form a sacrificial layer 511. After that, the surface is mechanically polished and planarized, and the process is performed until the insulator 526 is exposed (FIG. 3-1 (f)).

(7) The same processes as in (2) to (6) are repeated five times to sequentially stack the lower shield electrode 525, the middle electrode 522, and the upper shield electrode 524 (FIG. 3-2 (g)).

(8) The same process as (2) to (4) is performed to form the upper electrode 521 (FIG. 3-2 (h)).

(9) Photolithography is performed on the lower surface of the substrate 501 using a novolac resist to form an etching mask (not shown). Next, reactive ion etching (RIE) using a gas such as CF ₄ or CHF ₃ is performed to etch the silicon dioxide 507 to form an etching mask. Thereafter, the resist is removed (FIG. 3-2 (i)).

(10) RIE using inductively coupled plasma and BOSCH process is performed on the substrate 501 made of silicon from the lower surface to expose the silicon dioxide 507 on the upper surface serving as an etching stopper to form an opening 531 (FIG. 3-3 (j )). Here, the BOSCH process is a method in which silicon is selectively etched with good anisotropy by alternately supplying an etching gas and a sidewall protection gas and switching between etching and sidewall protection. By using this type of RIE, an opening 531 having a high aspect ratio can be formed. Specifically, SF ₆ (sulfur hexafluoride) is used as an etching gas, C ₄ F ₈ (tetrafluorocarbon ₈ ) is used as a side wall protecting gas, RF power: 1800 W, bias power: 30 W, gas Flow rate: SF ₆ = 300 sccm (Standard Cubic Centimeter), C ₄ F ₈ = 150 sccm, SF ₆ / C ₄ F ₈ gas switching time: 7 seconds / 2 seconds, substrate temperature: 10 ° C., etching time: 40 minutes Etching is good.

(11) The sacrificial layer 511 is wet-etched from the upper surface using heated TMAH (tetramethylammonium hydroxide) (FIG. 3-3 (k)).

(12) Reactive ion etching using a gas such as CF ₄ is performed from the lower surface, and the silicon dioxide 507 on the upper and lower surfaces are etched to form the through hole 530 (FIG. 3-4 (l)).

(13) From the lower surface, titanium / gold is continuously deposited at a thickness of 5 nm / 100 nm to form a shield electrode 529. Thereafter, electroless gold plating is performed to form gold (not shown) with a thickness of about 0.5 μm on each electrode surface. (Figure 3-4 (m)).

  Here, although the method of producing each electrode using plating has been described, each electrode made of copper may be produced using CVD (chemical vapor deposition).

  A charged particle beam lens in which an upper electrode, a middle electrode, and a lower electrode each having a plurality of openings are sequentially laminated, and a shield electrode having a plurality of openings is laminated between the upper electrode and the lower electrode In the method of manufacturing the array, a step of forming any one of the upper electrode, the middle electrode, the lower electrode, and the shield electrode using a plating technique or chemical vapor deposition, and a plurality of layers using sacrificial layer etching And the step of forming the opening can be manufactured by a micro-mechatronics technology based on a semiconductor process, and a charged particle beam lens array with high manufacturing accuracy can be realized.

<Description of components of electron beam exposure apparatus>
As Example 2 of the present invention, an electron beam exposure apparatus to which the electron lens array according to Example 1 can be applied will be described.
FIG. 4 is a schematic diagram of a main part of the electron beam exposure apparatus according to the present embodiment. In FIG. 4, reference numeral 1 denotes an electron gun, which includes a cathode 1a, a grid 1b, and an anode 1c. In the electron gun 1, electrons emitted from the cathode 1a form a crossover image between the grid 1b and the anode 1c (hereinafter, this crossover image is referred to as an electron source ES).

  The electrons emitted from the electron gun 1 become a substantially parallel electron beam by the condenser lens 2 whose front focal position is at the position of the electron source ES. The condenser lens 2 of the present embodiment has two sets (21, 22) of unipotential lenses composed of three aperture electrodes. The substantially parallel electron beam obtained by the condenser lens 2 enters the correction electron optical system 3. The correction electron optical system 3 includes an aperture array, a blanker array, a multi-charged beam lens, an element electron optical system array unit using the above-described electron lens array, and a stopper array. Details of the correction electron optical system 3 will be described later.

  The correction electron optical system 3 forms a plurality of intermediate images of the light source, and each intermediate image is reduced and projected by a reduction electron optical system 4 described later to form a light source image on the wafer 5. At this time, the correction electron optical system 3 forms a plurality of intermediate images so that the interval between the light source images on the wafer 5 is an integral multiple of the size of the light source image. Further, the correction electron optical system 3 varies the position of each intermediate image in the optical axis direction according to the field curvature of the reduction electron optical system 4, and each intermediate image is reduced and projected onto the wafer 5 by the reduction electron optical system 4. Aberrations that occur during the correction are corrected in advance.

  The reduction electron optical system 4 includes two sets of symmetric magnetic tablets, and each symmetric magnetic tablet includes a first projection lens 41 (43) and a second projection lens 42 (44). When the focal length of the first projection lens 41 (43) is f1, and the focal length of the second projection lens 42 (44) is f2, the distance between the two lenses is f1 + f2. The object point on the optical axis AX is at the focal position of the first projection lens 41 (43), and the image point is connected to the focal point of the second projection lens 42 (44). This image is reduced to -f2 / f1. In addition, since the two lens magnetic fields are determined so as to act in opposite directions, theoretically, the five aberrations of spherical aberration, isotropic astigmatism, isotropic coma aberration, field curvature aberration, and axial chromatic aberration are determined. Except for aberrations, other Seidel aberrations and chromatic aberrations related to rotation and magnification are canceled out.

  A deflector 6 deflects a plurality of electron beams from the correction electron optical system 3 to displace a plurality of light source images on the wafer 5 by substantially the same amount of displacement in the X and Y directions. Although not shown, the deflector 6 includes a main deflector used when the deflection width is wide and a sub-deflector used when the deflection width is narrow. The main deflector is an electromagnetic deflector, and the sub deflector is an electrostatic deflector.

  Reference numeral 7 denotes a dynamic focus coil, which corrects the focus position shift of the light source image due to deflection aberration generated when the deflector 6 is operated. Reference numeral 8 denotes a dynamic stig coil which, like the dynamic focus coil 7, corrects astigmatism of deflection aberration caused by deflection.

  Reference numeral 9 denotes a θ-Z stage on which a wafer is placed and can move in the optical axis AX (Z-axis) direction and the rotation direction around the Z-axis. A stage reference plate 10 and a Faraday cup 13 are fixed to the θ-Z stage 9. The Faraday cup 13 detects the charge amount of the light source image formed by the electron beam from the correction electron optical system 3. Reference numeral 11 denotes an XY stage, which is a stage on which the θ-Z stage 9 is mounted and is movable in the XY direction orthogonal to the optical axis AX (Z axis). A reflected electron detector 12 detects reflected electrons generated when the mark on the stage reference plate 10 is irradiated with an electron beam.

Next, the correction electron optical system 3 will be described with reference to FIG. FIG. 5A is a view of the correction electron optical system 3 viewed from the electron gun 1 side, and FIG. 5B is a cross-sectional view taken along the line AA ′ of FIG.
As described above, the correction electron optical system 3 includes the aperture array AA, blanker array BA, multi-charged beam lens ML, element electron optical system array unit LAU (ordered from the electron gun 1 side) along the optical axis AX. LA1 to LA4) and a stopper array SA.

  The aperture array AA has a plurality of openings formed in a substrate, and divides a substantially parallel electron beam from the condenser lens 2 into a plurality of electron beams. The blanker array BA is formed by forming a plurality of deflecting means for individually deflecting a plurality of electron beams divided by the aperture array AA on a single substrate. Details of one of the deflecting means are shown in FIG. The substrate 31 has an opening AP. A blanking electrode 32 is composed of a pair of electrodes sandwiching the opening AP and has a deflection function. Further, wiring (W) for individually turning on / off the blanking electrode 32 is formed on the substrate 31.

  Returning to FIG. 5, the multi-charged beam lens ML is used in the correction electron optical system 3 to increase the charged beam convergence effect.

  The element electron optical system array unit LAU is the electron lens array according to the present invention described above, which is formed by two-dimensionally arranging a plurality of electron lenses in the same plane. The electron optical system array LA2, the third electron optical system array LA3, and the fourth electron optical system array LA4 are included.

  FIG. 7 is a diagram for explaining the first electron optical system array LA1. The first electron optical system array LA1 is a multi-electrostatic lens including three pieces of an upper electrode UE, an intermediate electrode CE, and a lower electrode LE in which a plurality of openings are arranged, and is arranged in an upper, middle, and lower side along the optical axis AX direction. The electrode constitutes one electron lens EL1, a so-called unipotential lens. All the upper and lower electrodes of each electron optical system are connected at the same potential and set to the same potential (in this embodiment, the acceleration potential of the electron beam is set). The intermediate electrodes of the electron lenses arranged in the y direction are independently connected for each column by wiring (W). As a result, the potentials of the intermediate electrodes of the electron lenses arranged in the y direction can be individually set by the LAU control circuit 112 described later, whereby the optical characteristics of the electron lenses arranged in the y direction are set to be substantially the same. , Optical characteristics (focal lengths) for the respective electron lens groups arranged in the y direction are individually set. In other words, the electronic lenses arranged in the y direction and set to the same optical characteristic (focal length) are grouped together, and the optical characteristics (focal length) of the group arranged in the x direction orthogonal to the y direction are individually set. ing.

  FIG. 8 is a diagram for explaining the second electron optical system array LA2. The second electron optical system array LA2 is different from the first electron optical system array LA1 in that the intermediate electrodes of the electron lenses arranged in the x direction are independently connected to each other by wiring (W). As a result, the potential of each intermediate electrode of the electron lenses arranged in the x direction can be individually set by the LAU control circuit 112 described later, and the optical characteristics of the electron lenses arranged in the x direction are set to be substantially the same. The optical characteristics (focal length) for each group of electron lenses arranged in the direction are individually set. In other words, the electronic lenses arranged in the x direction and set to the same optical characteristic (focal length) are set as one group, and the optical characteristics (focal length) of the group arranged in the y direction are individually set.

  Since the third electron optical system array LA3 is the same as the first electron optical system array LA1, and the fourth electron optical system array LA4 is the same as the second electron optical system array LA2, their description is omitted. To do.

Next, the action that the electron beam receives by the correction electron optical system 3 described above will be described with reference to FIG.
The electron beams EB1 and EB2 divided by the aperture array AA enter the element electron optical system array unit LAU via different blanking electrodes. The electron beam EB1 passes through the electron lens EL11 of the first electron lens array LA1, the electron lens EL21 of the second electron lens array LA2, the electron lens EL31 of the third electron lens array LA3, and the electron lens EL41 of the fourth electron lens array LA4. The intermediate image img1 of the electron source is formed. On the other hand, the electron beam EB2 includes the electron lens EL12 of the first electron lens array LA1, the electron lens EL22 of the second electron lens array LA2, the electron lens EL32 of the third electron lens array LA3, and the electron lens EL42 of the fourth electron lens array LA4. Then, an intermediate image img2 of the electron source is formed.

  At this time, as described above, the electron lenses arranged in the x direction of the first and third electron lens arrays LA1 and LA3 are set to have different focal lengths, and the second and fourth electron lens arrays LA2 and LA4 are set. The electron lenses arranged in the x direction are set to have the same focal length. Furthermore, the combined focal length of the electron lens EL11, electron lens EL21, electron lens EL31, and electron lens EL41 through which the electron beam EB1 passes, and the electron lens EL12, electron lens EL22, electron lens EL32, and electron through which the electron beam EB2 passes. The focal length of each electron lens is set so that the combined focal length of the lens EL42 is substantially equal. Thereby, the intermediate images img1 and img2 of the electron source are formed at substantially the same magnification. Further, in order to correct the field curvature that occurs when each intermediate image is reduced and projected onto the wafer 5 via the reduction electron optical system 4, the intermediate images img1 and img2 of the electron source according to the field curvature. Are formed in different positions in the optical axis AX direction.

  Further, when an electric field is applied to the passing blanking electrode, the electron beams EB1 and EB2 change their trajectories as shown by broken lines in the figure, and cannot pass through the openings corresponding to the respective electron beams of the stopper array SA. The beams EB1 and EB2 are blocked.

  Next, a system configuration diagram of this embodiment is shown in FIG. The BA control circuit 111 is a control circuit that individually controls on / off of the blanking electrodes of the blanker array BA, and the LAU control circuit 112 is a control circuit that controls the electro-optical characteristics (focal length) of the lens array unit LAU. It is.

  The D_STIG control circuit 113 is a control circuit that controls the astigmatism of the reduction electron optical system 4 by controlling the dynamic stig coil 8. The D_FOCUS control circuit 114 is a control circuit that controls the focus of the reduction electron optical system 4 by controlling the dynamic focus coil 7. The deflection control circuit 115 is a control circuit that controls the deflector 6. The optical characteristic control circuit 116 is a control circuit that adjusts optical characteristics (magnification, distortion, rotational aberration, optical axis, etc.) of the reduction electron optical system 4.

  The stage drive control circuit 118 is a control circuit that drives and controls the XY stage 11 in cooperation with the laser interferometer LIM that drives and controls the θ-Z stage 9 and detects the position of the XY stage 11.

  The control system 120 controls each control circuit described above based on data from the memory 121 in which the drawing pattern is stored. The control system 120 is controlled by a CPU 123 that controls the entire electron beam exposure apparatus via an interface 122.

<Explanation of exposure operation>
Next, with reference to FIGS. 10 and 11, the exposure operation of the electron beam exposure apparatus according to the above-described embodiment will be described.
The control system 120 commands the deflection control circuit 115 based on the exposure control data from the memory 121, deflects a plurality of electron beams by the deflector 6, and commands the BA control circuit 111 to pattern the wafer 5 to be exposed. In response to this, the blanking electrodes of the blanker array BA are individually turned on / off. At this time, the XY stage 11 continuously moves in the y direction, and the deflector 6 deflects the plurality of electron beams so that the plurality of electron beams follow the movement of the XY stage.

  Each electron beam scans and exposes a corresponding element exposure region (EF) on the wafer 5 as shown in FIG. Since the element exposure area (EF) of each electron beam is set so as to be adjacent in two dimensions, as a result, a subfield (SF) composed of a plurality of element exposure areas (EF) that are exposed simultaneously is formed. Exposed.

  After exposing the subfield (SF1), the control system 120 instructs the deflection control circuit 115 to expose the next subfield (SF2), and the deflector 6 causes the direction orthogonal to the stage scanning direction (y direction). A plurality of electron beams are deflected in the (x direction). At this time, the aberration when each electron beam is reduced and projected via the reduction electron optical system 4 also changes due to the change of the subfield due to the deflection. Therefore, the control system 120 instructs the LAU control circuit 112, the D_STIG control circuit 113, and the D_FOCUS control circuit 114 to set the lens array unit LAU, the dynamic stig coil 8, and the dynamic focus coil 7 so as to correct the changed aberration. adjust. Then, as described above, the subfield (SF2) is exposed by exposing the element exposure region (EF) to which each electron beam corresponds. Then, as shown in FIG. 11, the subfields (SF <b> 1 to SF <b> 6) are sequentially exposed to expose the pattern on the wafer 5. As a result, on the wafer 5, a main field (MF) composed of subfields (SF1 to SF6) arranged in a direction (x direction) perpendicular to the stage scanning direction (y direction) is exposed.

Further, the control system 122 instructs the deflection control circuit 115 after exposing the main field 1 (MF1) shown in FIG. 11, and sequentially enters the main fields (MF2, MF3, MF4...) Aligned in the stage scanning direction (y direction). A plurality of electron beams are deflected and exposed. As a result, as shown in FIG. 11, a stripe (STRIPE1) composed of main fields (MF2, MF3, MF4...) Is exposed.
Then, the XY stage 11 is stepped in the x direction to expose the next stripe (STRIPE2).

  In a charged particle beam exposure apparatus, a charged particle source that emits a charged particle beam, a correction electron optical system that includes the charged particle beam lens array that forms a plurality of intermediate images of the charged particle source, and a plurality of intermediate images as exposure targets By having a projection electron optical system that performs reduction projection and a deflector that deflects a plurality of intermediate images projected on the exposure target to move on the exposure target, crosstalk for each particle beam can be reduced. it can.

  Next, a semiconductor device manufacturing process using the charged particle beam exposure apparatus according to the second embodiment will be described. FIG. 14 is a diagram showing a flow of an entire manufacturing process of a semiconductor device. In step 1 (circuit design), a semiconductor device circuit is designed. In step 2 (EB data conversion), exposure control data for the exposure apparatus is created based on the designed circuit pattern.

On the other hand, in step 3 (wafer manufacture), a wafer is manufactured using a material such as silicon. Step 4 (wafer process) is called a pre-process, and an actual circuit is formed on the wafer using lithography using the exposure apparatus and wafer to which the exposure control data has been input. The next step 5 (assembly) is called a post-process, and is a process for forming a semiconductor chip using the wafer produced in step 4, and is an assembly process (dicing, bonding), packaging process (chip encapsulation), etc. Process. In step 6 (inspection), the semiconductor device manufactured in step 5 undergoes inspections such as an operation confirmation test and a durability test. A semiconductor device is completed through these processes, and is shipped in Step 7.

The wafer process in step 4 includes the following steps. An oxidation step for oxidizing the surface of the wafer, a CVD step for forming an insulating film on the wafer surface, an electrode formation step for forming electrodes on the wafer by vapor deposition, an ion implantation step for implanting ions on the wafer, and applying a photosensitive agent to the wafer The resist processing step, the exposure step for printing and exposing the circuit pattern onto the wafer after the resist processing step by the above-described exposure apparatus, the development step for developing the wafer exposed in the exposure step, and the etching for removing portions other than the resist image developed in the development step Step, resist stripping step to remove resist that is no longer needed after etching. By repeating these steps, multiple circuit patterns are formed on the wafer.

It is a perspective view which shows the concept of the electron lens array which concerns on the Example of this invention. It is a figure for demonstrating the electronic lens array which concerns on the Example of this invention. It is a figure for demonstrating the electronic lens array which concerns on the Example of this invention. It is a figure for demonstrating the electronic lens array which concerns on the Example of this invention. It is a figure for demonstrating the manufacturing method of the electron lens array which concerns on the Example of this invention. It is a figure for demonstrating the manufacturing method of the electron lens array which concerns on the Example of this invention. It is a figure for demonstrating the manufacturing method of the electron lens array which concerns on the Example of this invention. It is a figure for demonstrating the manufacturing method of the electron lens array which concerns on the Example of this invention. It is a figure for demonstrating the optical system of the electron beam exposure apparatus which concerns on the Example of this invention. It is a figure which shows the correction | amendment electron optical system of the electron beam exposure apparatus which concerns on the Example of this invention. It is a figure for demonstrating the blanker array of the electron beam exposure apparatus which concerns on the Example of this invention. It is a figure for demonstrating the electron optical system array of the electron beam exposure apparatus which concerns on the Example of this invention. It is a figure for demonstrating the electron optical system array of the electron beam exposure apparatus which concerns on the Example of this invention. It is a figure for demonstrating the effect | action received with the correction | amendment electron optical system of the electron beam exposure apparatus which concerns on the Example of this invention. It is a figure for demonstrating the system configuration | structure of the electron beam exposure apparatus which concerns on the Example of this invention. It is a figure for demonstrating the exposure operation | movement of the electron beam exposure apparatus which concerns on the Example of this invention. It is a figure for demonstrating background art. It is a figure for demonstrating background art. It is a figure which shows the flow of the whole manufacturing process of a semiconductor device.

Explanation of symbols

AA: Aperture array, BA: Blanker array, ML: Multi-charged beam lens LAU: Element electron optical system array unit, LA (LA1 to LA4): Electro optical system array, SA: Stopper array, UE: Upper electrode, CE: Intermediate Electrode, LE: Lower electrode, EL: Electron lens, EB: Electron beam, LIM: Laser interferometer, AP: Opening, W: Wiring.
1: electron gun, 2: condenser lens, 3: correction electron optical system, 4: reduction electron optical system, 5: wafer, 6: deflector, 7: dynamic focus coil, 8: dynamic stig coil, 9: θ-Z Stage: 10: Stage reference plate, 11: XY stage, 12: Reflected electron detector, 13: Faraday cup, 21, 22: Unipotential lens, 31: Substrate, 32: Blanking electrode, 41, 43: First projection Lenses 42 and 44: second projection lens.
111: BA control circuit, 112: LAU control circuit, 113: D_STIG control circuit, 114: D_FOCUS control circuit, 115: Deflection control circuit, 116: Optical characteristic control circuit, 117: Stage drive control circuit, 120: Control system, 121 : Memory, 122: Interface, 123: CPU, 300: Electron lens array, 301: Electrode, 302: Fiber, 303: Shield electrode, 400: Electron lens array, 401: Electrode, 403: Shield electrode, 500: Electron lens array 501: Substrate 502: Seed layer 507: Silicon dioxide 508: Resist 509: Resist 510: Opening 511: Sacrificial layer 514: Opening 515: Voltage applying means 521: Upper electrode 522: Middle Electrode, 523: Lower electrode, 524: Upper shield electrode, 525: Shield electrodes, 526: insulating layer, 527: opening, 528: opening, 529: shield electrode, 530: through hole, 531: opening.

Claims (11)

In a charged particle beam lens array in which an upper electrode, a middle electrode, and a lower electrode each having a plurality of openings are sequentially arranged,
A shield electrode having a plurality of openings is disposed between at least one of the upper electrode and the middle electrode and between the middle electrode and the lower electrode,
The charged particle beam lens array, wherein the shield electrode has substantially the same shape as the middle electrode.   The charged particle beam lens array according to claim 1, wherein the shield electrode is electrically floating.   The charged particle beam lens array according to claim 1, wherein a voltage applying unit is connected to the shield electrode.   The charged particle beam lens array according to claim 1, wherein a voltage applying unit is connected to the middle electrode.   The charged particle beam lens array according to claim 1, wherein the middle electrode is electrically independent for each row of the openings.   6. The charged particle beam lens array according to claim 1, wherein an interval between the middle electrode and the shield electrode is 1/10 or less of a pitch of openings of the middle electrode.   7. A plurality of shield electrodes are disposed between at least one of the upper electrode and the middle electrode and between the middle electrode and the lower electrode. Charged particle beam lens array.   The interval between the middle electrode and the shield electrode is the smallest among the intervals between any two of the upper electrode, the middle electrode, the lower electrode, and the shield electrode. The charged particle beam lens array according to any one of 7. A charged particle source emitting a charged particle beam;
A correction electron optical system including the charged particle beam lens array according to any one of claims 1 to 8, wherein a plurality of intermediate images of the charged particle source are formed.
A projection electron optical system for reducing and projecting the plurality of intermediate images onto an exposure target;
A deflector for deflecting the plurality of intermediate images projected onto the exposure target so as to move on the exposure target;
A charged particle beam exposure apparatus comprising: In a method for producing a charged particle beam lens array in which an upper electrode, a middle electrode, and a lower electrode each having a plurality of openings are sequentially arranged,
A shield electrode having a plurality of openings is disposed between at least one of the upper electrode and the middle electrode and between the middle electrode and the lower electrode;
Forming any one of the upper electrode, the middle electrode, the lower electrode, and the shield electrode by plating or chemical vapor deposition;
Forming a plurality of the openings using sacrificial layer etching. A method for manufacturing a charged particle beam lens array, comprising:   A device manufacturing method comprising: a step of exposing an exposure target using the charged particle beam exposure apparatus according to claim 9; and a step of developing the exposed exposure target.

Images